1. Field of the Invention
This invention relates to an apparatus for clearing land mines and especially relates to a mine clearing apparatus mountable as an attachment to a bulldozer blade on a vehicle such as a tank. It particularly relates to a mine clearing rake, which is held at a controlled depth for uprooting both surface-laid mines and buried mines and shunting them to the sides of a full width cleared path through a minefield.
2. Review of the Prior Art
Many types of mine clearing apparatuses are known and have been put to use for clearing minefields. These apparatuses include flails, rollers and plows.
U.S. Pat. No. 2,486,372 describes an earth-working implement, such as an excavator, propelled by a combat tank for clearing minefields on land. The implement is a digger of the harrow type that includes a substantially V-shaped moldboard carrying a series of teeth, a horizontal beam lying across the front of the tank in the operative position, and a bar extending along the corresponding side of the vehicle to approximately the midpoint thereof.
U.S. Pat. No. 4,467,694 relates to a track width mine clearing apparatus for attachment to a vehicle and comprises a frame mountable onto a vehicle for selectable positioning in a raised or lowered orientation.
U.S. Pat. No. 4,491,053 describes an apparatus for track width clearing of mines that comprises a frame mountable onto a vehicle for selective positioning in a raised or lowered orientation, a plow apparatus for raising and shunting aside mines, and an apparatus for automatically raising or lowering the plow.
U.S. Pat. No. 4,590,844 discloses a track width mine clearing apparatus for attachment to a vehicle that comprises a selectively raised or lowered frame and an apparatus mounted on the frame for raising and shunting aside mines.
U.S. Pat. No. 4,667,694 relates to an apparatus for clearing light surface laid land mines that includes clearing plates which can freely move up and down independently of one another and are disposed in a movable carrier which is embodied as an attachment for a tracked or wheeled vehicle. The clearing plates are disposed at a slight distance from one another and are arranged in the direction of travel.
U.S. Pat. No. 4,690,030 describes a track width mine clearing apparatus for attachment to a vehicle that comprises a frame mountable on the vehicle, for selectable positioning in a raised or lowered orientation, and an apparatus mounted on the frame for raising and shunting aside mines, including a pair of angled arms having a profile complementary to that of the frame and the vehicle.
U.S. Pat. No. 4,727,940 describes a mine clearing apparatus for attachment to a vehicle and comprising a frame mountable on a vehicle for selectable positioning in a raised or lowered orientation and apparatus mounted o the frame for raising and shunting aside mines, including a plow section that defines a plurality of plow teeth which extend below the ground surface when in operation, and a conveyer apparatus extending along the length of the plow section and adapted to convey the contents of the earth raised by the plow section to one side of the vehicle.
U.S. Pat. No. 4,919,034 discloses a mine clearing apparatus for mounting onto a vehicle that comprises a support adapted to be rigidly fixed to the vehicle and at least one elongate plough blade extending transversely of the path of forward travel of the vehicle and mounted on the support so that each blade is pivotable about a first axis which extends transversely of the path, the plough blade being pivotable also about a second axis which extends substantially perpendicularly to the first axis and approximately parallel to the path of travel of the vehicle.
U.S. Pat. No. 4,938,114 relates to a track width plowing means for dislodging, uplifting, and sweeping aside mines, this means being attached to a crossbeam and located on either side of float shoes that slide along the ground and adjust to maintain a chosen depth of plow, the crossbeam being connected to the front of a vehicle by pushbars that attach to a frame mounting on the vehicle.
All of these devices are adversely affected by power limitations imposed by the choice of push vehicle which limits the width of cleared lane or the depth from which mines can be cleared. In response to this limitation for a tracked combat tank, most devices attempt to clear only a track width lane on each side to allow passage of the tank. Since modern mines are effective against the full width of the tank and since following vehicles cannot travel exactly in the path of the clearing vehicle, track width clearing devices have limited effectiveness in creating a breach through a mine field. The few devices which attempt to clear the entire width of the pushing vehicle are faced with disposing of the large amount of spoil material which accumulates on the moldboard of the apparatus. Those devices which use teeth to lift mines from the soil deposit the mines along with the spoil against a moldboard. All of these apparatuses tend to be heavy if designed to clear land mines and are likely to be seriously damaged by detonation of a mine. Such detonation is also likely to occur in close proximity to the vehicle, whereby the vehicle could be disabled.
Mine detonation under or against a mine clearing apparatus is likely to so damage the apparatus as to not only render it ineffective but also cause the device to severely impede the movement of the vehicle. Since such an event is likely to occur while the vehicle is being fired upon by an adversary, it is highly desirable that the crew be able to disengage the mine clearing apparatus quickly without dismounting from the vehicle.
The heavy weight of these devices, the weight of the spoil and the difficulty of pushing large teeth through the soil to lift buried mines has resulted in power/transmission requirements so severe that no standard combat vehicle can push prior art full width clearing apparatus to excavate and remove buried mines from a mine field. There is accordingly a need for a mine clearing device that is: a) spaced relatively far from the treads and underside of the vehicle, b) is relatively light but unusually rigid and strong, c) includes a means for minimizing blast effects created by detonation of a land mine, thereby protecting both the rake and the propelling vehicle, d) does not have to push excessive amounts of spoil, e) can be disengaged from within the pushing vehicle and f) is easily repairable.